I have a number of products that must meet the requirements of EN 61000-3-3 for voltage fluctuation but I am having problems complying. The failure happens when a vacuum pump is switched on during a cycle of the machine and then it is switched off. The inrush that occurs is about 35 amps with a running current of 5 amps. We switch the pump on and off with a SSR zero crossing. I would like to solve this problem with the least cost to meet the test requirement. I have tried powering the pump with a 25ohm power resistor in series and a time delay relay to switch the resistor out. This works reasonably well and reduces the inrush to 10 amps but the time delay relay I am using is about $60 and it doesn't have a high enough current rating for the contacts to use it in production. I will be getting in a Crydom SST soft start relay combination to try but it has other implementation problems such as my control voltage is +24 Vdc and it is rated to +10 Vdc plus the soft start module is not VDE approved so it might not have the creepage require to satisfy the safety guys. Does anyone have a suggestion such as a certified soft start relay or some elegant fix that I could implement. I would appreciate any comments or personal triumphs in solving flicker problems. The circuit specs are; AC input 200-240Vac, pump current 5 amps, control +24Vdc.
Thanks, Ray Levasseur EMC Compliance CreoScitex _________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: [email protected] Dave Heald [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on "Virtual Conference Hall,"
